Aqueous metastable dispersion of tetravalent organo-tin compounds treating process



UIIII,

AQUEOUS META'STABLE DISPERSION OF TETRA- VALENT ORGANO-TIN COMPOUNDS TREAT- ING PROCESS Lawrence C. Leatherland, Columbus, Ohio, assignor, by mesne assignments, to Permachem Corporation, West Palm Beach, Fla., a corporation of Florida No Drawing. Filed June 7, 1957, Ser. No. 664,176 20 Claims. (Cl. 117-1385) This invention relates to a method for treating fibrous materials to render these materials resistant to pestiferous organisms coming into contact therewith. More particularly, the invention is concerned with a process including a contacting of the fibrous material with a metastable, aqueous dispersion containing a tetravalent organo-tin compound and a surface-active agent and a breaking of the metastable, aqueous dispersion while in contact therewith to thereby deposit the organo-tin compound on the fibrous material.

The utility of fibrous materials coated or impregnated with biocidal agents is well known. For example, textiles may be treated with antifungal compounds to render the textile fungi-resistant. Uniformity of the application of the biocidal agent to the material to obtain uniform coating or impregnation is desirable so that the imparted properties are uniform throughout the material. Additionally, the treated article should retain the imparted properties for normal periods of usage. In the case of textiles, for example, the treated textiles should have laundering resistance so that substantial loss of imparted properties will not occur upon washing. A treatment for an article that renders the article more or less permanently toxic to bacteria and fungi coming into contact therewith is highly useful. Such treatment permits preparation of articles that should, of necessity, be maintained in a sterile condition. Additionally, deteriorating and destructive elfects of pestiferous organisms on the material themselves leading to moulding, mildew, decay, and the like, may be avoided.

Various materials and compounds are known to have suitable properties for control of various pestiferous organisms. For example, organo-tin compounds are known to have antifungal properties and also to be useful in the control of insects, including moths. Recently tetravalent organo-tin compounds have been shown to exhibit antibacterial action. Thus, organo-tin compounds now appear to be ideal multipurpose agents for use in the control of pestiferous organisms, such as fungi, yeast, protozoa, bacteria, insects, etc. It should be understood that the term pestiferous organisms is used, for lack of a better term, to include microand macroorganisms which have deleterious efiects upon both natural and artificial fibrous materials or their use. However, while tetravalent organo-tin compounds have been known for some years to have fungitoxic and mothproofing properties, the use of the same has been handicapped due to the substantial water insolubility of these tetravalent organo-tin compounds. Generally, these tetravalent organo-tin compounds would have to be dissolved in a nonaqueous solvent for treatment of materials with the obvious toxic and fire hazards of such solvents. Thus, usage was limited to a greater extent than if a suitable process existed for utilization of an aqueous medium containing these compounds.

It has now been discovered that tetravalent organo-tin compounds may be readily applied tofihrous material by contacting the fibrous material with an aqueous meta- 2,957,785 Patented Oct. 25, 1960 stable dispersion containing an organo-tin compound and a surface-active agent and by subjecting the metastable dispersion while in contact with the material to heat to break the dispersion and thus deposit an organo-tin compound on the material. This process permits the use of aqueous media containing an organo-tin compound and avoids many restrictions of prior art processes Where nonaqueous solvents were necessary. Additionally, the process permits the preparation of fibrous articles having improved laundering resistance. Where media containing tetravalent organo-tin compounds and surface-active agents are used to treat fibrous materials, by processes such as wetting the material with the media and then drying the fabric, apparently there are deposits on the material the organo-tin compounds and also substantial amounts of surface-active agents which, upon laundering of the material, as by rewetting, tend to redisperse the organo tin compounds and carry the organo-tin compounds away during the laundering. By the process of this invention, little or no surface-active agent is deposited along with the organo-tin compound and any tendency of any deposited surface-active agent to redisperse the organo-tin material upon laundering is minimized or eliminated with improved laundry resistance of materials being obtained by the process of the invention. By improved laundry resistance there is meant a minimization of loss of the organo-tin compound from the treated material upon repeated laundering.

The organo-tin compounds with which this invention is concerned are tetravalent organo-tin compounds. These tetravalent organo-tin compounds are characterized as being substantially water-insoluble and, when mixed solely with water, separate into separate phases of organo-tin compounds and water, upon cessation of the mixing action. If these organo-tin compounds are dissolved in a common organic solvent, such as acetone, methyl alcohol, etc., and then diluted solely with water, there generally results a substantial separation of the mixture into phases with the organo-tin compounds separating from the aqueous phase. These tetravalent organo-tin compounds are further characterized by being organic compounds of tin in a tetravalent state, having at least one organic radical linked to the tin atom through a carbon atom. The organic radicals may be substituted or unsubstituted, saturated or unsaturated alkyl, aryl, arylalkyl, or hetercyclic radicals. The preferred tetravalent organo-tin compounds are those compounds having three organic radicals, each radical linked to the tin atom through a carbon atom, and, preferably, these organic radicals are alkyl radicals having a sum total for the three radicals of from 9 to 12 carbon atoms, as these compounds appear to have the most effective properties for resisting pestiferous organisms. Valences of the tetravalent tin atom not satisfied by organic radicals linked to the tin atom through a carbon atom are satisfied by negative radicals or elements. These negative radicals or elements may be monovalent or divalent and include negative radicals or organic and inorganic acids and other negative radicals or elements, such as hydroxyl, oxygen, sulfur, etc., which combine with tin. Thus the tetravalent organo tin compounds may be carboxylates, 'such as acetates, formates, etc.; they may be salts of inorganic acids, such as sulfates, halides, etc.; and they may also be oxides, sulfides, etc. Suitable tetravalent organo-tin compounds containing these various negative radicals or elements are quite numerous and well known to those skilled in the art. For purposes of illustration and not limitation, suitable representative tetravalent organo-tin compounds include the following: tetrabenzyl tin, tetraethyl tin, triethyl-n-octyl tin, tribenzylphenyl tin, triethyl-n-octyl tin, triethyltin fluoride, trimethyltin propionate, tributyl-tin acetate, tributyltin hydroxide, diethylphenyltin acetate, tributyltin oxide, tritliiiiil methyltin acetate, triethyltin chloride, triethyltin hydroxide, triethyltin cyanide, triethyltin acetate, triethyltin benzoate, triethyltin phenoxide, triethyltin methanesulphonamide, triethyltin p-nitrophenoxide, triethyltin toluene-p-sulphone-acetate, N-triethylstannylphthalimide, tri-n-propyltin acetate, triisopropyltin acetate, tripentyltin palmitate, tri n hexyltin acetate, tri-n octyltin acetate, triphenyltin acetate, diethyl-p-bromophenyltin acetate, diethyl-p-chlorphenyltin acetate, tris-p-chlorophenyltin acetate, diethyl-n-octyltin iodide, diethyl-noctyltin acetate, diethyl-n-octyltin oxide, diethyl-ndodecyltin acetate, ethyldi-n-pentyltin acetate, dibutyltin dichloride, dibenzyltin dichloride, dibutyltin oxide, methylethyltin distearate, diheptyltin dilaurate, ethyltin tributyrate, propyltin trioleate, octyltin trihexoate, ec.

The aqueous metastable dispersions suitable for the process of the invention comprise water, an organo-tin compound, and a surface-active agent. The aqueous metastable dispersions are characterized by being initially substantially stable at ordinary temperatures, but being able to be subsequently broken by subjecting the dispersions to heating, so that an organo-tin phase separates from the dispersion. These aqueous metastable dispersions include the various types of colloidal systems that may be made with either liquid or solid tetravalent organo-tin compounds and surface-active agents.

The aqueous metastable dispersions are well suited for the process for coating or impregnating fibrous material, because they are substantially stable at ordinary temperatures, but able to be subsequently broken by heating. Since the dispersions are uniform and stable at ordinary temperatures they may be handled and shipped without any extraordinary precautions and a fibrous material may be uniformly and thoroughly wet at ordinary temperatures by simple processes, such as immersing and soaking. A subsequent heating of the dispersion while in contact with the fibrous material places the formerly stable dispersion in an unstable state so that anorgano-tin compound phase separates uniformly therefrom and is uniformly deposited on or impregnated in the fibrous material. A removal of the fibrous material from the heated broken dispersion leaves behind in this dispersion the bulk of the water, most of the surface-active agent and a minor part of the organo-tin compound. The removed fibrous material contains a minor part of the water, a minor part of the surface-active agent, and a major amount of the organo-tin compound. Subsequent drying of this treated fibrous material gives a treated product which has very little surfaceactive agent thereon along with the organo-tin compound. This treated product is an improved product with improved laundry resistance in that during laundering very little surface-active agent is present to redisperse the organo-tin compound with subsequent loss of the same from the treated material.

The aqueous metastable dispersions of the invention do not appear to be true solutions but appear to be colloidal in nature since they exhibit the well known Tyndall effect. Many of the dispersions are clear in appearance and appear to be the same as water upon cursory, visual examination. The clear aqueous metastable dispersions are preferred as they are of unusual value in certain applications.

To prepare these dispersions, generally the organo-tin compound is dispersed in a surface-active agent and this stock dispersion admixed with an amount of water to obtain an aqueous metastable dispersion containing the organo-tin compound in the desired amount for application by the process of the invention. A tetravalent organo-tin compound may be added to a surface-active agent or a surface-active agent may be added to an organo-tin compound and this mixture agitated as for example by stirring until the composition is uniform throughout. This stock composition may then be admixed with water to obtain an aqueous metastable dispersion for use in accordance with this invention stock composition and the metastable dispersions may be prepared with only moderate stirring or agitation. The use of mixing devices which produce a high shearing stress preferably are avoided. Preparation of the dispersions may be accomplished readily with a conventional apparatus, such as paddle or propeller stirrer. Where the organo-tin compound is in a solid state, the compound may be finely divided, and then readily dispersed in the surface-active agent and water. Various known methods may be used to get the solid tetravalent organo-tin compounds in a finely divided state for subsequent dispersion. An organo-tin compound may be dissolved in a small amount of a water-miscible organic liquid and the organic liquid containing the dissolved organo-tin compound may then be readily dispersed in the surface-active agent and then subsequently admixed with water to obtain the desired aqueous metastable dispersion. The preferred methods are chemical processes for preparation of the solid organo-tin compound in a finely divided state. For example, an aqueous metastable dispersion containing a dispersed liquid organo-tin compound, such as tributyl tin oxide, is treated with an acid, such as acetic acid, to convert the liquid organo-tin compound to a solid organotin compound. Where the organo-tin compound is in a liquid state the compound may be readily dispersed in the surface-active agent to obtain an emulsion of fine globules of the liquid organo-tin compound in the surfaceactive agent and this emulsion may be subsequently admixed with water to obtain an aqueous metastable emulsion, which is included within the term aqueous metastable dispersion as used throughout the specification and the claims.

While the aqueous metastable dispersions suitable for the process of the invention always contain water, at least one organo-tin compound, and at least one surface-active agent, other materials may be included. For example, two or more compatible tetravalent organo-tin compounds or two or more compatible surface-active agents may be present. Also a small amount of a resinous adhesive may be included to increase the 'fastness of the organo-tin compound to the fibrous material. While the iaunderability of material treated by the process of the invention is adequate for most purposes, a resinous adhesive may afford a superior retentiveness of the organo-tin compound to the material. The amount of resinous adhesive that may be included may be varied widely, may be many times the amount of the organotin compound, and is determined by the hand of the fabric desired. Various adhesive resins known to the art are suitable. These resinous adhesives include polystyrene, poiyvinyl esters, vinylidene copolymers, etc. Necessarily the resinous adhesive need be compatible with the organo-tin compound and the surface-active agent. Preferred are those resinous adhesives that may be dispersed readily in the aqueous metastable dispersions of the invention.

Other compatible materials may be added to the aqueous metastable dispersions of the inventions where desired. For example, the following materials, where compatible, may be added: water-softening agents; optical bleaches; germicides, fungicides, etc. other than organotin compounds; dyes and pigments; and so forth.

Numerous surface-active agents of various types have been found to be suitable for preparing the aqueous metastable dispersions for the process of the invention. These suitable surface-active agents include those classed as amphoteric, nonionic, anionic and cationic surface-active agents. Generally, at least 0.3 to 10 or more parts by weight of a surface-active agent to 1 part by weight of the organo-tin compound are used, with l to 6 parts by weight of the surface-active agent the preferred amounts. The minimum amount of surface-active agent to be used varies somewhat apparently depending on the nature of the particular surface-active agent and the particular tetravalent organo-tin compound.

Suitable selection of a surface-active agent may be made with due consideration for the organo-tin compound used and the desired temperature for breaking the dispersion. For example, a ready determination may be made by those skilled in the art as to which among the various known surface-active agents are suitable. The essential requirements for suitable surface-active agents are twofold and it may be readily determined which surface-active agents have these properties. First, the surface-active agent should be capable of making an aqueous colloidal dispersion of the particular organo-tin compound and this dispersion should be substantially stable at normal conditions. By normal conditions are meant the customary prevalent atmospheric conditions of temperature, humidity, and so forth and the customary conditions, such as storage, shipping, routine handling, shelf life and so forth. By substantially stable at normal conditions it is meant there should be no noticeable breaking or separation of an organo-tin phase other than that which may be readily redispersed by moderate agitation or stirring and that no substantial breaking or separation should occur within periods of time as short as one to two hours. Preferably, the dispersions are clear but a cloudy dispersion apparently is not deleterious in the practice of the process of the invention. Secondly, the aqueous colloidal dispersion prepared with a particular surface-active agent should be capable of being broken by the particular temperature that is desired to be used. For example, if it is desired to break an aqueous colloidal dispersion by heating to a certain temperature, the colloidal dispersion may be heated to this temperature and if a separation of the organo-tin phase occurs then the surface-active agent is a suitable surface-active agent for preparation of the aqueous metastable dispersion for the process of the invention. It is necessary to define the suitable surface-active agents as those which have these two essential characteristic properties because the extensive study for selection of amount of a tetravalent organo-tin compound that should be used to prepare an aqueous metastable dispersion varies and apparently is dependent on the nature of the particular agent and particular compound. Also the amount of surface-active agent affects the temperature at which the dispersion may be broken, with larger amounts of surface-active agent generally requiring somewhat higher temperatures to break the dispersion.

While suitable surface-active agents and temperatures for breaking the same may be readily selected by those skilled in the art in light of the teachings of this application, for purposes of illustration of the large choice of suitable surface active agents and not for limitation thereof, there are tabulated in Table 1 suitable surfaceactive agents for forming aqueous metastable dispersions of an organo-tin compound and specific temperatures for breaking the resultant aqueous metastable dispersions.

The fibrous materials that may be treated by the process of the invention are numerous and varied. For example, to mention only a few, threads, yarns, fibers, rope, hemp, wool, cotton, rayon, cellulose esters and ethers, nylon, silk, Dacron, cloth, toweling, felt, fabric, rugs, fibrous insulation, burlap, bandages, gauze, textiles, wood pulp, paper, etc., may be treated. Other fibrous articles and materials will be obvious to those skilled in the art and in light of the teachings of this invention are included within the scope of this invention. The term textile as used in the specification and claims includes fabricated articles of fibrous materials, such as yarn, thread, rope, etc. as well as woven, knitted or felted materials and the fibers therein may be of natural origin, such as animal or vegetable fibers or may be of synthetic origin such as synthetic resin fibers.

The process of the invention comprises contacting a fibrous material with an aqueous metastable dispersion and subjecting the dispersion while in contact with the material to a change in temperature to break the dispersion and thereby cause an organo-tin phase to separate TABLE 1 AQUEOUS METASTABLE DISPERSIONS CONTAINING 500 P.P.M. TRIBUTYL TIN OXIDE Surface-Active Agent Chemical Name or Class Commercial Source Suitable Ratio, Surface- Breaking Active A v n Temperature Tributyl Tin F.) Oxide (By Weight) Polyioxyethylene lauryl ether o fln Poly ethylene glycol 400 monolaurate fl Fatty acid amide ether derivative Polyoxyethylated vegetable oil *1. Bril 30," Atlas Powder Company, Wilmington, Delaware. 2. Glyco Products 1110., Brooklyn, N.Y. 3. Nonisol 100, Alrose Chemical Co., Providence, RI. 4. Span 20, 4a; "Span 40, 4b; Span 60, 4c;

Span Mo. 6.

- 5100, Emulsol Corp., Chicago, Ill.

9. Synthetlcs AF-100, Hercules Powder Co., Wilmington, Del. 10. Tween 20, Atlas Powder Co., Wilmington, Del. 11. LlgglYlMlig, E.

Carbon Chemical Co., Emulphor ISL-719,"- Antara suitable surface-active agents has shown there are numerous suitable surface-active agents with apparently no other characterizing properties common to all.

The ratio of the amount of surface-active agent to the Spraying,

80, Atlas Powder 00., Wilmington, Delaware. 5. Sterox CD, Monsanto Chemical Co., St. Louis, Allpol 00-436, Antara Chemicals Div., General Dyestuft Corp., New York, N .Y. 7. Emlcol 8. Modicol S, 8a; Nopco 1408, Nopco Chemical Co., Harrison, N .J

F. Drew & Co., New York, N.Y. 12. Tergitol NPX, Carbide dz 13. Miragene T Cone, Miranol Chemical Co., Irvington, N .J l4.

Chemicals Dlv., General Dyestufi Corp., New York, N.Y.

and deposit or impregnate on or in the material. The contacting of the material, such as a textile, may be by various known methods such as immersion, dipping, brushing, etc. Customary methods known to the art may be used. The dispersions are broken by heating the dispersion while in contact with the material to a temperature where the dispersion breaks with an organo-tin compound phase separating therefrom. The temperature for breaking the metastable dispersion is less than the boiling temperature of the dispersion and preferably is more than 100 F. and less than 200 F. A suitable selection of a breaking temperature for the process may be made by suitable selection of the surface-active agent and its ratio to the particular organo-tin compound desired to be used. The use of elevated or reduced pressures is within the scope of the process and breaking temperatures may be varied by the same. Temperatures of less than 100 F. generally are not suitable because environmental changes may be sufficient to break the metastable dispersion and necessitate the control of the environment. Temperatures of higher than about 200 F. generally are not suitable because of rapid loss of water from the aqueous metastable dispersion with subsequent difiiculty in controlling the concentration of the organo-tin compound in the dispersion and deposition of the requisite amount of organo-tin compound on the fibrous material.

The preferred embodiment of the process of the invention comprises immersing a textile in :an aqueous metastable dispersion and heating the dispersion having the textile immersed therein to a temperature where the dispersion breaks. The textile then is removed from the heated dispersion, and adhering thereto, or in the case of porous fibrous materials also impregnated therein, will be organo-tin compound. The textile then is dried or processed in manners well known to the art. The preferred process is Well suited for incorporation or practice in a conventional dyebeck apparatus and process.

One embodiment of the process of the invention comprises depositing a liquid alkaline tetravalent organo-tin compound, such as tributyl tin oxide, by contacting a fibrous material with an aqueous metastable dispersion and breaking the dispersion while in contact with the fibrous material, and then subsequently contacting the deposited liquid organo-tin compound with a suitable acid to convert it to a solid tetravalent organo-tin compound. The acid may be added to the heated dispersion having the treated fibrous material therein, or the treated fibrous material may be removed from the heated dispersion and subsequently treated with the acid. Where the treated material is removed fromthe heated dispersion for subsequent treatment with the acid, the treatment may comprise immersion of the treated material in a dilute acid solution or may comprise exposure of the treated material to the vapor of the acid. Suitable acids for conversion of liquid alkaline organo-tin compounds to solid organo-tin compounds may be selected by those skilled in the art. For example, acetic acid or sulfuric acid or phosphoric acid convert liquid tributyl tin oxide to the corresponding solid organo-tin acetate, sulfate, or phosphate.

Generally the process is best carried forth in a batch manner of treatment. However, the process may be adapted to a continuous manner of treatment and continuous processes are within the scope of the invention. For example, a textile may be thoroughly wet with a metastable dispersion by passing through the same, the wetted textile then passed through a heated zone to raise the temperature of the wetted textile to the breaking temperature of the dispersion, the wetted textile separated from the major amount of the heated broken dispersion clinging thereto, such as by passing through pressure rolls, and then the textile dried to obtain a treated textile by a continuous process of the invention.

The requisite amount of an organo-tin compound, that needs to be deposited on a fibrous material to impart thereto suitable antipestiferous properties, may range from only a few parts per million up to several thousand parts per million of the organo-tin compound per part by weight of the fibrous material, depending on the particular pestiferous organism. Amounts in excess of several thousand parts per million generally fail to noticeably increase the antipestiferous properties and only increase the cost of treatment. Amounts of less than a few parts per million frequently do not impart satisfactory antipest-iferous properties. The minimum amount of an organo-tin compound needed to impart suitable antipestiferous properties to a textile appears to be dependent on the thickness and density of the textile. In the case of textiles, 50 to 500 parts per 'million of an organo-tin compound per part by weight of the textile impart satisfactory antipestiferous properties for most purposes. The amount of an organo-tin compound in the aqueous metastable dispersion may be varied considerably. In practice it has been found for most fibrous materials that for the aqueous metastable dispersion to contain a suitable amount of an organo-tin compound, the tetravalent organo-tin compound should be present in the dispersion in an amount about 50 percent greater than desired to be deposited on the fibrous material. The nature of the particular fibrous material being treated has at effect on the exhaustion or depletion of the metastable dispersion and accordingly affects the amount of organotin compound that should be contained in the metastable dispersion. For example, cotton and wool appear to exhaust about percent of the tributyltin oxide contained in an aqueous metastable dispersion, while nylon, Dacron, and filament rayon exhaust slightly below 50 percent. In the practice of the process of the invention the amount of aqueous metastable dispersion per amount of fibrous material may be varied considerably. In practice of the process in a batch manner it has been found that ratios by Weight of the dispersion to the fibrous material of from 20:1 to 60:1 are suitable.

' This invention will now be described further with reference to specific examples. All proportions listed in the following example are parts by weight.

Example I The following composition was prepared:

Parts Tributyltin oxide 1 Polyethylene glycol 400 monolaurate (molecular weight 400) (sold by Glyco Products Co., New

York, New York) 3 The tributyltin oxide was added to the polyethylene glycol monol'aurate with stirring for approximately 10 minutes to obtain a clear dispersion. This clear dispersion was then mixed with 116 parts of water and stirred approximately 10 minutes to obtain a stock composition of a clear aqueous dispersion that showed no settling after standing one hour. 2.5 parts of this stock solution was then mixed with 2000 parts of Water to obtain a clear aqueous metastable dispersion for the process of the invention.

There is a possibility the organo-tin compound called a tributyltin oxide in this and the following examples may be either a tributyltin hydroxide or a tributyltin oxide or a mixture of tributyltin hydroxide and tributyltin oxide. The tributyltin oxide possibly may be of such a structure that there is an oxygen bridge between two tributyltin radicals. The compound called tributyltin oxide may be prepared by agitating an ether solution of a tributyltin halide with an aqueous potassium hydroxide solution, separating the ether solution from the aqueous solution, and then removing the ether from the ether solution to obtain what has been called a tributyltin oxide. Apparently depending on the exact conditions of the ether removal and the conditions for storage of the compound one may obtain either tributyltin oxide or tributyltin hydroxide or a mixture of the same. Accordingly, where throughout the specification and the claims the term tributyltin oxide is used there is included with- 9 in said term tributyltin oxide, tributyltin hydroxide, and mixtures of the same.

A first sample of 100 parts of knitted cotton underwear was immersed inthe clear aqueous metastable dispersion and permitted to soak for five minutes with the dispersion at room temperature. The temperature of the dispersion was then raised to 125-130 F. by application of heat over a period of about 15 minutes and the dispersion and cotton underwear therein held at 125-430 F. for 20 minutes. The cotton underwear was then removed from the heated dispersion and dried.

A clear aqueous metastable dispersion was prepared as above with 2.5 parts of the stock solution. A second sample of 100 parts of cotton underwear was treated in the same manner as the first except after the 20 minutes at 125-130 F., the dispersion and underwear therein was cooled to 115120 F. and held at this temperature for 15 minutes as a softening operation before removal from the heated dispersion and drying.

Upon test of the treated samples of cotton underwear both samples showed about 200 parts per million of tributyltin oxide per part by weight of the treated cotton underwear.

- Example II A stock composition was prepared as in Example I except that the clear dispersion of one part of tributyltin oxide and three parts of polyethylene glycol. 400 monolaurate was mixed with 76 parts of water to obtain the stock composition of a clear aqueous dispersion of Example II. 2.5 parts of this stock dispersion of Example Iland 3000 parts of water were mixed to obtain the clear aqueous metastable dispersions of Example II.

A first and second sample of cotton hose, each 100 parts by weight, were then immersed in the clear aqueous metastable dispersions of Example II using the same procedure as that of Example I for the first and second samples of cotton underwear.

Upon test of the treated cotton hose samples, each sample showed about 300 parts per million of tributyltin oxide per part by weight of the treated cotton hose.

Tributyltin oxide Polyoxyethylene lauryl ether (sold as Brij 30 by Atlas Powder Co., Wilmington, Delaware) 3 The tributyltin oxide and the olyoxyethylene lauryl ether were mixed with moderate stirring to obtain a concentrate of a clear stable dispersion. This concentrate was stable after over four months of storage at room temperature conditions. Minor amounts of this concentrate, when admixed with major amounts of water, gave aqueous metastable dispersions which broke when heated to 125 to 130 F.

0.1 part of this concentrate was mixed with 3000 parts of water to obtain an aqueous metastable dispersion, and 100 parts of bleached cotton print cloth were immersed therein. With the cloth immersed therein the dispersion was heated from 75 F. to 125 F. in 15 minutes and held at 125 to 130 -F. for 15 minutes. At this time the cloth was removed from the heated dis persion and dried.

part of this concentrate was mixed with 3000 parts of I Water to obtain an aqueous metastable dispersion, and 100 parts of bleached cotton print cloth were immersed therein. With the cloth immersed in the metastable dispersion the dispersion was heated from 75 to 125 F. and held at 125 to 130 F. for 15 minutes. At this time the cloth was removed from the heated dispersion and immersed for 15 minutes at 75 1 percent Example V The following concentrate composition was prepared:

Parts Water 32 Polyoxyethylene sorbitan monopalmitate (sold as Tween 40 by Atlas Powder Company, Wilmington, Del-aware) 34 20% acetic acid 17 Tributyltin oxide 17 All of the above were added in the order shown and mixed to obtain a concentrate of an aqueous dispersion. The tributyltin oxide and acetic acid in solution reacted to form tributyltin acetate and this concentrate, accordingly, contained tributyltin acetate. This concentrate was stable after over one month of storage at room temperature conditions. 0.15 part of this concentrate was mixed with 3000 parts of water to obtain an aqueous metastable dispersion containing tributyltin acetate, and parts of bleached cotton print cloth were immersed therein. With the cloth immersed in the metastable dispersion the dispersion was heated from 75 to F. in 15 minutes and held at 125 to F. for 15 minutes. At this time the cloth was removed from the heated dispersion and dried.

Example VI The following composition was prepared:

Parts Tributyltin oxide 1 Polyethylene glycol 400 monolaurate (Sold by Glyco Products Company, New York, New York) 4 The tributyltin oxide and polyethylene glycol 400 monolaurate were mixed thoroughly. Aqueous metastable dispersions were prepared by mixing .125 part of this composition and 2000 parts of water.

100 parts by weight of a cotton cloth were treated according to the process of the invention by immersing the cloth in an aqueous metastable dispersion of this ex ample, raising the temperature of the dispersion having the cloth therein to 125 to 130 F., to break the dispersion, holding the temperature of 125 to 130 F. for 15 minutes, and then removing the cloth from the hot broken dispersion. Chemical analysis of the dispersion before and after treatment of the cotton cloth showed the tin content of the dispersion was exhausted about 75 percent after treatment of the cotton cloth.

In the same manner 100 parts by weight of a wool cloth were treated according to the process of the invention using an aqueous metastable dispersion of this example and upon chemical analysis of the dispersion before and after treatment of the wool cloth it was found the tin content was exhausted about 75 percent after treatment.

In the same manner nylon cloth, Dacron cloth, and filament rayon were treated and upon chemical analysis of the dispersions before and after treatment, it was found in each instance the tin content was exhausted slightly less than 50 percent.

Example VII A stock composition was prepared as in Example I and permitted to stand at room temperature for several weeks. After this period of standing the stock composition had become cloudy or milky in appearance. This stock com position Was stirred moderately and then aqueous metastable dispersions were prepared therefrom according to the procedure for preparing the same in Examples I and 11 II. These clear aqueous metastable dispersions were then used to treat a first sample of cotton underwear and a first sample of cotton hose according to the procedures for the same in Examples I and II.

Example VIII The following composition was prepared:

Parts Tributyltin oxide 1 Alkyl phenyl polyethylene glycol ether (Sold as Tergitol NPX anhydrous by Carbide & Carbon Chemical Corporation, New York, New York) 6 These two components were mixed to obtain a clear aqueous dispersion. 0.11 part of this clear aqueous dispersion was added to 1500 parts of tap water to prepare a clear aqueous metastable dispersion of this example.

A piece of cotton print cloth about 9 in. by 72 in., 50 parts by weight, was placed in the metastable dispersion of the example and the dispersion having the cloth therein was heated to about 140 F. and maintained between 140 to 150 F. for 15 minutes. The hot dispersion was then drained from the cloth and replaced with 1500 parts of tap water containing parts of a phosphoric acid solu tion of a concentration of 1 part of acid per 1000 parts of solution and this solution and the cloth agitated for minutes. The tap water solution of phosphoric acid was then drained from the cloth and the cloth dried in a household clothes dryer.

A piece of nylon fabric, 48.8 parts by weight, was treated in the same manner as the piece of cotton print cloth.

A hank of s cotton yarn, 23 parts by weight, was treated in the same manner as the piece of cotton print cloth.

Example IX The following composition was prepared:

Parts Water 600 Fatty acid amide ether derivative (Sold as Miragene T. Cone, by Miranol Chemical Co., Irvington, N. I.) 0.48 Tributyltin oxide 0.16

These components were added and mixed in the order as listed to obtain the aqueous metastable dispersion of this example.

A bleached cotton cloth, 15.7 parts by weight, was immersed in the aqueous metastable dispersion of this example with the dispersion at room temperature. The dispersion having the cloth therein was heated to 170 to 180 F. and maintained at this temperature for 20 min utes. The dispersion was drained from the cloth and replaced by a mixture of 580 parts of tap water and 20 parts of an aqueous phosphoric acid solution containing one part of 85% phosphoric acid per 1000 parts of water and the cloth maintained in this mixture for 15 minutes at room temperature. At this time the cloth was removed from the mixture and dried at 105 to 110 C. for 10 minutes.

Example X The following composition was prepared:

Parts Water 1,500 Alkyl phenyl polyethylene glycol ether (Sold as Tergitol NPX by Carbide & Carbon Chemicals Corporation, New York, New York) 2.25 Tributyltin chloride 0.375

The above components were added and mixed in the order as listed to obtain the aqueous metastable dispersion of this example.

A bleached cotton print cloth, 49.4 parts by weight, was immersed in the aqueous metastable dispersion of this example with the dispersion at room temperature. The dispersion having the cloth therein was heated to 12 to F. and maintained at this temperature for 15 minutes. The heated dispersion was then removed from the cloth and the wet treated cloth dried in a household automatic clothes dryer.

Example XI An aqueous metastable dispersion was prepared as in Example X.

A bleached cotton print cloth, 49.6 parts by weight, was immersed in this aqueous metastable dispersion with the dispersion at room temperature. The dispersion having the cloth therein was heated to 140 to 150 F. and maintained at this temperature for 15 minutes. The heated dispersion was then removed from the cloth, and the wet cloth placed in an aqueous solution, 1500 parts by weight, containing 0.25 part of disodium phosphate at room temperature for 15 minutes. This aqueous solution was then removed from the cloth and the wet treated cloth dried in a household automatic clothes dryer.

Example XII The following composition was prepared:

Parts Water 1,250 Polyethylene glycol 400 monolaurate (Sold by Glyco Products Company, New York, New

York) 0.6 Isopropyl alcohol solution containing 20% Dibutyltin dilaurate 1.0

Example XIII The following composition was prepared:

Parts Water 20 Styrene copolymer emulsion (Sold as Polyco 380 by The Borden Company, New York, New York) 20 Alkyl phenyl polyethylene glycol ether (Sold as Tergitol NPX by Carbide & Carton Chemicals Corporation, New York, New York) 5 Tributyltin oxide l The above listed components were mixed to obtain a stock composition. An aqueous metastable dispersion was obtained by mixing 1.4 parts of this stock composition with 2500 parts of water. A second aqueous metastable dispersion was obtained by mixing 0.9 part of this stock composition with 2500 parts of water.

A first sample of cotton cloth, 100 parts by weight, was immersed in the first aqueous metastable dispersion for five minutes with the dispersion at room temperature. The dispersion having the cotton cloth therein was then heated to about F. and held at this temperature for 20 minutes. The cotton cloth was then removed from the heated dispersion and dried at 210 to 230 F.

In the same manner as the first sample of cotton cloth, a second cotton cloth, 100 parts by weight, was treated using the second aqueous metastable dispersion.

Example XIV 2.5 Tnbutyltin oxide The above components were mixed to obtain the aqueous metastable dispersion of this example.

A length of cotton duct, 8 oz. per yard, was moved through the aqueous metastable dispersion of this example at a speed where the cotton duck cloth picked up about 0.7 part of the dispersion per part of cloth. The cotton duck cloth then continued to move into a first heated zone maintained at a high humidity and at a temperature of about 140 to 150 F. and remained in this heated zone about 3-6 minutes. At this time the heated fabric passed from the first heated zone through pressure rolls and a portion of the heated dispersion was removed from the cloth. The cloth then continued to move into a second heated zone maintained at a low humidity and a temperature of 180 to 200 F. and remained in this second zone for a time sufiicient to dry the treated cloth.

The utility and superiority of fibrous materials treated by the process of the invention may be shown in a variety of ways. For example, the utility may be shown by various testing procedures which measure the degree of efi'ectiveness of the treated material against various pestiferous organisms. For example, the superiority of the treated materials may be shown by the improved laundry resistance of the treated materials when compared to materials treated by other processes. This superiority may be measured by chemical analysis of the amount of organo-tin compound retained on the treated fibrous material after a number of launderings or by test of the effectiveness of the treated material after a number of launderings.

The treated materials of the preceding examples were tested for their biocidal and inhibitory growth eifect on various pestiferous organisms, such as bacteria or fungi. All of the treated materials of the preceding examples in these tests had a biocidal effect or an inhibitory growth elfect on at least one or more pestiferous organisms.

For example, in Table 2 there are given the results of a part of these tests for some treated materials of the proceding examples. A sizeable sterile zone surrounding the test disk. on the agar plate inoculated with Micrococcus pyogenes, variety aureus, indicates bactericidal activity. The absence of a sterile zone around the test disks on the inoculated plates and the presence of no overgrowth or only a small overgrowth on the disks shows the inhibition of the growth of the bacteria.

TABLE 2 M. aureus Treated Sample Sterile Zone, Av. Over- Diameter, growth 2 1st Sample, knitted cotton underwear of EX I..- 23.0 1st Sample, cotton hose of Ex. II 29+ 0 Bleached cotton Print Cloth of Ex. IIL. 17.0 0 Bleached cotton Print Cloth of Ex. IV.- 16.8 0 Bleached cotton Print Cloth of Ex. V 16. 3 0 1st Sample, knitted cotton underwear of Ex. VII. 19. 5 0 1st Sample, cotton hose of Ex. VIL- 22.0 0 Cotton Print Cloth of Ex. VIII 31. 7 0 Nylon fabric of Ex. VIII 16.0 0 Untreated Sample, cotton eloth 0 4+ Test disk diameterzle mm.

Overgrowth rated from 0:110 overgrowth to 4+:overgrowth after 14 days.

Fibrous materials treated by the process of the invention are resistant to pestiferous organisms coming into contact therewith and have an inhibitory effect on such organisms. Bactericidal efiectiveness may be demonstrated by tests with M icrococcus pyogenes, variety aureus. Fibrous materials and articles treated according to the present invention are toxic to most bacteria and have been observed to kill a large number of difierent types of bacteria.

Uniform methods, which are described in the paragraphs which follow, were used to prepare cultures of the test organism and to make the tests. These testing procedures are especially adapted to tests on insoluble pesticidal agents, such as tetravalent organo-tin compounds.

A nutrient broth for M. pyogenes was prepared consisting of 5 grams of dehydrated beef extract, 10 grams of dehydrated peptone, 5 grams of sodium chloride, and 1000 milliliters of distilled water. This broth was boiled for 30 minutes, adjusted to pH 6.8 with 1N NaOH, boiled an additional 10 minutes, and diluted to its original volume of distilled water.

A stock culture medium for M. pyogenes was prepared by adding 1.5 percent by weight of bacto-agar, based on the Weight of the broth, to the broth, adjusting the pH to 7.4, and autoclaving at 15 p.s.i. pressure and 121 C. for 20 minutes.

Cultures of M. pyogenes were grown in the stock culture media and transferred to the nutrient broths for incubation prior to testing. In each test a loopful of the culture was transferred from the stock culture medium to a 10 milliliter portion of nutrient broth, incubated for 24 hours at 37 C., and a loopful transferred from the first to a second 10 milliliter portion of nutrient broth. The culture was incubated in this manner in three successive broths, at which time it was ready for use as an inoculum. A portion of this inoculum was diluted to times the original volume, and 0.1 milliliter samples of the diluted inoculum streaked over the surfaces of solidified agar on plates with bent glass rods. At least four plates, one of which served as a control, were inoculated with each organism.

Toxicity of fibrous materials treated according to this invention against the various pestiferous organisms was determined by cutting test disks of the fibrous material and placing'the test disks on agar plates immediately after they have been inoculated with the respective test organisms. Eifectiveness is indicated by the presence of a sterile zone on the agar plate in the area surrounding the disk of fibrous material, or the lack of overgrowth of organism on the disk after incubation for seven days.

The superiority of the fibrous materials treated by the process of the invention can be shown by the effectiveness of the treated material against various pestiferous organisms after a number of repeated launderings.

One laundering procedure comprised cutting samples of a standard size, generally for a textile about 4 in. by 6 in. Each sample was then placed in an individual 6 oz. container along with 75 milliliters of an aqueous 0.5 percent sodium oleate solution and 10 small steel balls. The containers were then attached to the agitator blades of an apartment-size Montgomery Ward washing ma chine and agitated for 15 minutes with water of about F. in the washing machine. After this washing each sample was removed from the container, wrung by hand, and rinsed in cold running water for 5 minutes. Then the wet sample was placed in a clean container with a fresh sodium oleate solution and 10 balls and the test repeated. After the final washing the samples were given three separate rinses in running cold water and dried.

In the following Table 3 there are tabulated tests for some of the treated matenialsof the examples. The laundering procedure described in the preceding paragraph was utilized and the uniform testing procedure for eifectiveness against bacteria described previously was utilized. These tests results show materials treated by the process of the invention have a superior effectiveness against M. aureus when compared to an untreated sample and a sample of a treated cloth prepared by a process other than the process of the invention.

The superiority of the fibrous materials treated by the process of the invention also can be shown by chemical analysis of the tin content of the treated material after a number of repeated launderings. Analyses were made of some of the treated materials of the examples after a number of launderings according to the aforedescribed laundering procedure. Similarly analyses were made of fibrous materials treated by a process other than the process of the invention after the same number of repeated launderings. The fibrous materials treated by the process of the invention showed a smaller proportional loss in tin content than samples treated by other processes after the same number of repeated launderings.

It is to be understood that the foregoing specification is by way of illustration and not by way of limitation, and that the scope of the invention shall be limited only by the scope of the appended claims.

1 overgrowth rated from no overgrowth to 4+ overgrowth after 14 days.

1 Approximately 3 yards of a bleached cotton cloth were immersed in a dispersion at room temperature, permitted to soak therein for minutes, removed, wrung by hand, and dried. The dispersion utilized comprised 4500 parts of water containing 9 parts of a stock concentrate consisting of 140 parts of water, parts of tributyltin oxide, and 40 parts of a polyethylene lauryl ether, sold as Brij by Atlas Powder Company. Wilmington, Delaware.

What is claimed is:

1. A method for treating a fibrous material to render it resistant upon repeated launderings, to pestiferous organisms coming into contact therewith, which includes:

contacting the material with an aqueous metastable dispersion of a tetravalent organo-tin compound, said dispersion consisting essentially of water, the tetravalent organo-tin compound, and a surface-active agent; and breaking the aqueous metastable dispersion while in c011- tact with the material by application of heat to deposit the organo-tin compound on the material.

2. The method of claim 1 including removing the material from contact with the heated dispersion.

3. The method of claim 1 in which said fibrous material is a cellulosic material.

4. The method of claim 1 in which said fibrous material is a textile.

5. A method for treating a fibrous material to render it resistant upon repeated launderings to pestiferous or- .ganisms coming into contact therewith, which includes: immersing the material in an aqueous metastable dispersion of a tetravalent organo-tin compound, said dis persion consisting essentially of water, the tetravalent .organo-tin compound, and a surface-active agent; and heating the dispersion having the material therein to a temperature of from 100 to 200 F. sufiicient to break the dispersion to deposit the organo-tin compound on the material.

6. The method of claim 5 including withdrawing the treated material from the heated dispersion.

7. A method for treating a fibrous material to render it resistant upon repeated launderings to pestiferous organisms coming into contact therewith, comprising: contacting the material with an aqueous metastable dispersion of a tetravalent organo-tin compound, said disper sion consisting essentially of major amount of water and minor amounts of the tetravalent organo-tin compound and a surface-active agent with at least 0.3 part by weight of said surface-active agent for each part by weight of said organo-tin compound; heating the aqueous metastable dispersion while in contact with said mate- 12. The method of claim 7 in which said organo-tin compound is tributyl tin acetate.

13. The method of claim 7 including drying said material after removal from contact with the heated dispersion.

14. A method for treating a fibrous material to render it resistant upon repeated launderings to pestife-rous organisms coming into contact therewith, comprising: preparing an aqueous metastable dispersion by dispersing a minor amount of a liquid alkaline tetravalent organo-tin compound in a major amount of water containing a minor amount of a surface-active agent and mixing therein a minor amount of an acid to convert said liquid organo-tin compound to a solid tetravalent organo-tin compound; contacting the fibrous material with the prepared aqueous metastable dispersion; breaking said dispersion while in contact with said material by application of heat to deposit the organo-tin compound on the material; and removing said material from contact with the heated dispersion.

15. The method of claim 14 in which said liquid alkaline tetravalent organo-tin compound is tributyl tin oxide.

16. A method for treating a fibrous material to render it resistant upon repeated launderings to peStifer ous organisms coming into contact therewith, comprising: contacting the material with an aqueous metastable dispersion containing a liquid alkaline tetravalent organotin compound and a surface active agent; breaking said dispersion while in contact with said material by application of heat to deposit said liquid organo-tm compound on said material; and contacting the deposited liquid organo-tin compound with an acid, whereby sa d deposited liquid organo-tin compound converts to a solid tetravalent organo-tin compound.

17. The method of claim 16 in which said liquid alkaline tetravalent organo-tin compound is tributyl tin oxide.

18. The method of claim 17 in which said acid is acetic acid.

19. The method of claim 17 in which said acid 18 phosphoric acid. 2 0. A product consisting essentially of a fibrous mate- 1 7 rial having a tetravalent organo-tin compound deposited thereon, said product after repeated launderings being characterized by resistance to pestiferous organisms and being that product resulting from the process of claim 1.

OTHER REFERENCES 5 Journal of Applied Chemistry (London), vol. 4, 1954, References Cited in the file of this patent pages 314318, Investigations on Organo-Tin Compound. UNITED STAiES PATENTS III. The Biocidal Properties of Organo-Tin Com- 2,157,727 Baker May 9, 1939 pounds, by Van Der Kerk and Luijten. Copy in Patent 2,635,060 ChI'OIliS et a1. Apr. 14, 1953 10 Office Library,

UNITED STATES PATENT OFFlCE CERTIFICATE OF CORRECTION Patent No; 2,957 785 October 25, 1960 Lawrence C. Leatherland It is herebfi certified that error appears in the-printed specification of the above numbered patent requiring correction and that the said- Letters Patent should read as corrected below.

Column 2, line 57, for "radicals or" read radicals of column 3, line 15, for "ec." Bead etc. column 8 line 22, for "at effect" read an effect Signed and sealed this 25th day 0'1 April 1961,

(SEAL) Attest:

DAVID L. LADD ERNEST W. SWIDER Commissioner of Patents Attesting Oflicer 

1. A METHOD FOR TREATING A FIBROUS MATERIAL TO RENDER IT RESISTANT UPON REPEATED LAUNDERINGS, TO PESTIFEROUS ORGANISMS COMING INTO CONTACT THEREWITH, WHICH INCLUDES: CONTACTING THE MATERIAL WITH AN AQUEOUS METASTABLE DISPERSION OF A TETRAVALENT ORGANO-TIN COMPOUND, SAID DISPERSION CONSISTING ESSENTIALLY OF WATER, THE TETRAVALENT ORGANO-TIN COMPOUND, AND A SURFACE-ACTIVE AGENT, AND BREAKING THE AQUEOUS METASTABLE DISPERSION WHILE IN CONTACT WITH THE MATERIAL BY APPLICATION OF HEAT TO DEPOSIT THE ORGANO-TIN COMPOUND ON THE MATERIAL. 